“Strange the formation of the eely race That know no sex, yet love the close embrace. Their folded lengths they round each other twine, Twist amorous knots, and slimy bodies joyn; Till the close strife brings off a frothy juice, The seed that must the wiggling kind produce. Regardless they their future offspring leave, But porous sands the spumy drops receive. That genial bed impregnates all the heap, And little eelets soon begin to creep.”
Pliny, after making the assertion (taken, as usual, from Aristotle) that among fish the females are larger, and often the more numerous, goes on, an echo once more of “His Master’s Voice,” to deny to the Eel sex, either masculine or feminine: according to him, Eels when they had lived their day, rubbed themselves against the rocks, and their scrapings came to life: “they have no other mode of procreation.”[616]
Von Helmont attributed the birth of Eels to the dews of May mornings! other authors deduced their parentage from the hairs of horses! others again from the gills of fish! while the great Izaak Walton insisted on spontaneous generation![617]
To solve the insoluble, recourse was, as usual, had to the gods: thus Jupiter and a white-armed goddess yclept Anguilla[618] (the Latin for Eel) were accounted parents of the countless “cousins to the snake.”
Theory was piled upon theory, false conclusions were drawn from falser data. Even as late as 1862 appeared an author, not one whit less certain of the truth of his discovery based “on a series of observations extending over sixty years,” or one whit less active in asserting it, than any of his numerous predecessors.
In The Origin of the Silver Eel, Mr. D. Cairncross propounded the following assertion: “The progenitor of the silver Eel is a small beetle: of this I feel fully satisfied in my own mind, from a rigid and extensive comparison of its structure and habits with those of other insects.”[619] “The beetle in the act of parturition” is represented on the [frontispiece]!
The fact that this beetle is evidently a dead one would not, as the Bibliotheca Piscatoria rather wickedly puts it, even if known to the writer, cause him to alter his opinion one jot!
It was only in 1896—strange, indeed, that a problem which so many keen intellects had attacked should remain unelucidated for over two thousand years!—that the mode of reproduction and development of the Eel was first surmised, and then for the most part ascertained by Professor Grassi and Dr. Galandruccio. But not till 1904 were most of the surmises of the Italian investigators placed beyond question, and the mode of reproduction, etc., established beyond doubt by Johann Schmidt of Copenhagen.
The now accepted view (stated shortly) is as follows: fresh-water Eels approach maturity when about six years old, and then change their colour from browny-yellow to silver, whence “Silver Eels.” In this bridal attire and with eyes enlarged, they find their way from the rivers to the sea, and far out into deep waters of the ocean. The pace at which they travel on their way to the sea cannot be computed exactly, but two marked Eels have been caught whose record was nineteen kilometres in two days. Meek[620] states that neither the exact locality nor the approximate depth of the spawning is as yet known, but that there can be no doubt that the spawning region lies deep and far out in the Atlantic beyond the Continental shelf.
The Times, Sept. 25, 1920, announces that Dr. J. Schmidt has just discovered the spawning place of fresh-water Eels to be not far S. of Bermuda, or about 27 deg. N. and 60 deg. W., much farther W. than he anticipated. Of the many marvels of the ichthyic world this is, perhaps, the greatest. It taxes, it transcends, our powers adequately to conceive the hereditary instinct or gauge the enduring strength which impels fish—as yet sexually undeveloped—of only moderate size to traverse 3000 or 4000 miles of an ocean full of foes, and to seek, especially to find, the only area which contains the requisite depth, temperature, and currents favouring the procreation and the return home of their minute but parentless progeny.